The effect of SO2 on the vesicular–arbuscular mycorrhizae associated with a submontane mixed grass prairie in Alberta, Canada

Abstract

We investigated the effect of long-term exposure to sulphur-based acid-forming emissions (primarily sulphur dioxide) on a submontane mixed grass prairie and the associated vesicular–arbuscular mycorrhizae (VAM). Three prairie field sites were selected at distances of 5, 13, and 20 km from a sour gas processing plant that had been operating for approximately 23 years. The sites were selected for similarity of vegetation and soils. The soil at site 1 showed symptoms of acidification as did the soil from site 2, but to a lesser extent. The VAM inoculum potential was also significantly lower in soil from site 1, and to a lesser extent from site 2, compared with soil from site 3. These results are discussed in terms of the effects of sulphur dioxide on the field sites and its subsequent effect on the VAM.